DE 199 61 617 A1; DE 199 51 966 A1 or DE 101 42 625 A1 have made known a neck rest which has a strut member which can be displaced towards the front on the seat user's head, and an impact member actuating the strut member. When there is an impact onto the rear end of the vehicle the impact member will be actuated and the strut member is displaced towards the front. The strut member is supported on the cushion holder via pivoting arms. In DE 199 51 966 A1, the strut member forms part of the neck rest cushion which consists of two components which are connected to each other via joints. The impact member can interact with the strut member via a pull rope and can be in communication with a release element.
DE 102 08 620 describes a neck rest for the seats of automobiles which has a fixed support portion and a second support portion for a movable cushion component which is movably supported in the first support portion. The second support portion is pivotally supported about a lower horizontal axis in the first support portion and an actuation device is defined by a spring which biases the second support portion. A controllable locking device maintains the second support portion in the retracted position on the first support portion. A third support portion is supported to be displaced on the second support portion between a lower and an upper position. The third support portion is biased by a second spring towards the upper position. A second controllable locking device maintains the third support portion in the lower position with the second locking device being released when the second support portion has reached a predetermined pivoting angle. This design is intended to help in achieving an optimum load absorption with no risk for the seated person to be injured during a rear-end collision.
Neck rests of this type are also referred to as crash-active neck rests. Their characteristic feature is that a seat user's head which will bounce back during a crash moves through a distance which is as short as possible until it hits against the neck rest. This distance possibly is relatively long when a passive neck rest is used and there is a risk for the head not to be supported at the proper point so that backbone lesions cannot be ruled out.
The disadvantage of the extendable neck rests which are known is that they comprise multiple elements. This involves relative large expenditure for their manufacture, specifically for its cushion. Moreover, their appearance possibly is not very pleasing because there is a circumferential gap between the adjacent components of the known crash-active neck rest.